Breeding programs for smallholder sheep farming systems: I. Evaluation of alternative designs of breeding schemes

Optimization of alternative breeding schemes for the genetic improvement of common Tigray highland sheep in northern Ethiopia

BACKGROUND

Genetic improvement is one of the major means to enhance the productivity of livestock, and well-designed animal genetic improvement schemes are necessary to achieve genetic gains. The objective of the current study was to design an alternative breeding program to improve the productivity of common Tigray highland sheep. Two village- and two central nucleus-based breeding schemes were simulated and evaluated in terms of genetic gain, bio-economic efficiency and operational feasibility.

METHODS

Four breeding schemes were simulated: scheme 1, a one-tier cooperative village-based breeding scheme, scheme 2, a two-tier cooperative village breeding scheme (dispersed village-based nuclei scheme), scheme 3, a central open nucleus-based scheme with 5% nucleus size; and scheme 4, a three-tier breeding schemes (central open nucleus-based linked with multiplier units). Simulation analyses were performed using the ZPLAN computer program, which is based on a deterministic approach to estimate genetic and economic gains in the breeding programs.

RESULTS

Between the two village-based breeding schemes, scheme 2 showed higher genetic gain and economic efficiency in the breeding traits analysed than scheme 1. The central nuclei schemes were more efficient than the village breeding schemes. Scheme 3 was the most efficient with a genetic gain in the breeding objective of US $ 1.03 and a profit of US $ 2.73/ewe/year, but operationally it is also the most difficult to implement as it requires a big central nucleus. A central nucleus linked with the village-based nuclei would be a feasible option to overcome the operational difficulties of the conventional central nucleus schemes. If a village-based breeding program is considered it should be the first step in most low-input systems. In this case, scheme 2 is the most efficient.

CONCLUSIONS

With some support from the public sector at the outset and a strong collaboration among the stakeholders including smallholders, scheme 4 could lead to substantial genetic gains in the common Tigray highland sheep breed within its habitat that covers large areas of the Tigray region. Therefore, we recommend a long-term breeding program which should include cross-breeding, genomic selection, updated estimates of genetic and economic values for the common Tigray highland sheep breed.

Community-Based Livestock Breeding: Coordinated Action or Relational Process?

Over the past decade, community-based breeding programs (CBBPs) have been promoted as a viable approach to improving smallholder livelihoods through a systematic livestock breeding. CBBPs aim to initiate systematic breeding at the community level, including an organized animal identification and recording of performance and pedigree data. To ensure the breeding programs' continuity, building capacities, and ownership among participants are essential to the approach. This study's purpose was to understand how CBBPs have evolved in specific institutional settings and which dynamics occur in the course of implementation. We addressed these questions in reflective conversations with six coordinators of a diverse sample of CBBPs: goats (Malawi, Uganda, and Mexico), sheep (Ethiopia), alpaca (Peru), and cattle (Burkina Faso). The interviews and analysis were guided by categories of the multi-level perspective. The respondents considered lack of funding and weak institutionalization as the main constraints on the CBBPs. While the idea of participation and localized ownership was at the center of the programs, linear paradigms of knowledge transfer prevailed. In all cases, the impulse to start a CBBP came from individual researchers, who relied on intermediaries, such as extension agents, for implementation. Personal relations and trust were seen as both a factor in the success and a positive outcome of CBBPs. We conclude that these findings have different implications depending on how rural development is conceptualized: proponents of the innovation systems perspective would call for stakeholders to further align their interests and coordinate their actions. Proponents of process-relational concepts, in contrast, would not consider the CBBP a product but a starting-point for initiators and participants to continuously discover new ways of collaboration and engagement.

Bio-economic and operational feasibility of introducing oestrus synchronization and artificial insemination in simulated smallholder sheep breeding programmes

Low selection intensity due to few selection candidates available at any one time due to thinly spread year-round lambings in villages and prohibitively large nucleus requirements to provide sufficient improved rams to the production tier are the major challenges for designing effective village-based and central nucleus-based breeding programmes, respectively, for smallholder sheep farmers. To tackle these challenges, we used deterministic simulation to design three schemes in village-based programmes introducing hormonal oestrus synchronization (natural oestrus (VNE), single oestrus synchronization (VSE1) and double oestrus synchronization (VSE2)) and three schemes in central nucleus programme introducing artificial insemination (AI) (natural mating with nucleus sizes of 5% (CNM1) and 1% (CNM2) of the total ewe population and natural mating in breeding tier and AI in production tier (CAI)). The schemes were evaluated for their bio-economic and operational feasibility, taking Bonga sheep of Ethiopia as a case study. The selection intensities achieved in VNE, VSE1 and VSE2 were 2.0, 2.3 and 2.4, respectively, for selecting rams for the breeding tier and 0.0, 0.8 and 1.0, respectively, for the production tier. The profits per ewe per year from VNE, VSE1 and VSE2 were Birr 12.2, 21.7 and 24.5, but the profit from VNE for the production tier was zero. CAI generated more genetic gains in the breeding objective (Birr 4.8) than CNM1 (Birr 2.5) and CNM2 (Birr 0.0) in the production tier. However, CAI was less profitable than CNM1 and CNM2. In conclusion, hormonal oestrus synchronization was found to be a feasible technological aide to accelerate genetic progress in village-based programmes. CNM1 and CNM2 could not be recommended as CNM1 requires large nucleus of 10 325 ewes and CNM2 results in zero genetic gain in the production tier. CAI could overcome the challenge in central nucleus programmes, namely unaffordable large nucleus, but the scheme needs to be subsidized by the public sector to be economically feasible for farmers.

Review: Sustainability of crossbreeding in developing countries; definitely not like crossing a meadow…

Crossbreeding, considering either terminal or rotational crossing, synthetic breed creation or breed replacement, is often promoted as an efficient strategy to increase farmers' income through the improvement of productivity of local livestock in developing countries. Sustainability of crossbreeding is however frequently challenged by constraints such as poor adaptation to the local environment or lack of logistic support. In this review, we investigate factors that may influence the long-term success or the failure of crossbreeding programs, based on the scientific literature and country reports submitted for The Second Report on the State of the World's Animal Genetic Resources for Food and Agriculture. Crossbreeding activities vary widely across species and countries. Its sustainability is dependent on different prerequisites such as continual access to adequate breeding stock (especially after the end of externally funded crossbreeding projects), the opportunity of improved livestock to express their genetic potential (e.g. through providing proper inputs) and integration within a reliable market chain. As formal crossbreeding programs are often associated with adoption of other technologies, they can be a catalyst for innovation and development for smallholders. Given the increasing global demand for animal products, as well as the potential environmental consequences of climate change, there is a need for practical research to improve the implementation of long-term crossbreeding programs in developing countries.